Phenological Characterization of Forest Vegetation in Russia (the Krasnoyarskii Krai) Based on Satellite Data

Abstract

The present study addresses phenology of forest vegetation based on satellite data, by analyzing the relationship between the long-term (2003-2016) series of NDVI of coniferous and deciduous tree stands and climate in the Krasnoyarskii Krai (Russia). The source data were the 8-day satellite data from MODIS (the MOD09Q1 product) and weather data from land-based weather stations. Positive trends were revealed for the average NDVI values of deciduous trees between May 1 and 16. This correlated with the trend of the accumulated air temperature (above + 5 °С) from January through May. The long-term variations in the dates of the onset of conifer seasonal growth were estimated using average NDVI values of the new shoots between May 17 and June 1: the difference between the average NDVI values of coniferous trees after the onset of the seasonal growth (June 1) and the NDVI values before the onset of the seasonal growth (May 17). Positive trends were obtained for the average NDVI values of the new shoots on coniferous trees. A tendency towards an earlier onset of the seasonal growth was obtained for a 14-year period of time.